Toxicological and environmental aspects of carrot fly (Psila rosae Fabr.) control 119 Pestycydy, 28, (1-2), 119-126. ISSN 28-873 Toxicological and environmental aspects of carrot fly (Psila rosae Fabr.) control Stanisław SADŁO 1, Małgorzata FILAR 2 and Ewa SZPYRKA 3 1 University of Rzeszów, Department of Biotechnology, 26 Sokołowska St., 36-1 Kolbuszowa, Poland e-mail: sadlo@univ.rzeszow.pl 2 Alima-Gerber S.A., 1 Gen. Maczka St., 35-959 Rzeszów, Poland 3 Institute of Plant Protection, Experimental Station, 28 Langiewicza St., 35-11 Rzeszów, Poland Abstract: The objectives of this work were to describe the residual behaviour of chlorpyrifos (insecticide) and chlorothalonil (fungicide), applied for the protection of carrot and parsley plantations. The field tests were carried out at farms located near Rzeszów (South-Eastern Poland) on processing carrot and parsley destined for baby food production. The results obtained indicated that disappearance rate of chlorothalonil on carrot leaves was significantly faster and its half-life time was about 7 times shorter than that of chlorpyrifos. In weather conditions of 26, chlorpyrifos residues in rape carrot and parsley roots were reduced to levels lower than MRL and even the rigorous value of.1 mg/kg. Keywords: residues, chlorpyrifos, chlorothalonil, carrot and parsley INTRODUCTION Consumers exposure to pesticides used for the treatment of crops is of growing health concern, especially in case of infants and young children that represent the most vulnerable group of human population (high food consumption per body weight unit and yet undeveloped detoxication mechanism). Therefore uniform residue limit as low as.1 mg/kg was established by Commission Directive 1999/39/EC for any pesticide in baby food [1]. In order to estimate and than to minimize the risk of placing on the market such products containing
12 S. Sadło, M. Filar, E. Szpyrka harmful residues, studies on the decline of kinetics of pesticide residues in fruit and vegetables seem necessary. The paper reports the results of tests which aim to describe the residual behaviour of chlorpyrifos (insecticide) and chlorothalonil (fungicide), applied for the protection of carrot and parsley plantations. MATERIALS and METHODS The field tests were carried out in 26 at farms located near Rzeszów (South-Eastern Poland) on processing carrot and parsley destined for baby food production. The treatments against second generation of carrot fly (P. rosae Fabr.) were performed within the third decade of July using Nurelle D 55 SC (active ingredients: chlorpyrifos and cypermethrin). Because of high pressure of powdery mildew (Erysiphe heraclei DC.) Bravo Plus 5 SC was applied and then included in the study. Rainfall data were obtained from Meteorological Station of the Institute of Meteorology and Water Management (IMGW) in Jasionka Airport near Rzeszów. The first samples (four carrot plants and four soil samples) were taken immediately after treatments. Pesticide residues were extracted with acetone, transferred to dichlorometane and determined by using the 689 Agilent apparatus equipped with capillary columns, chemstation and nitrogen phosphorous (NPD) and electron capture (ECD) detectors [2-5]. Pesticide residue levels were evaluated in relation to their Maximum Residue Levels/Limits (MRLs) [6-1]. RESULTS and DISCUSSION Chlorpyrifos is a toxic crystalline organophosphate insecticide that inhibits acetylcholinesterase. The substance acts primarily by contact activity and as a stomach-poison. In Poland chlorpyrifos is mainly used under the tradenames Nurelle D 55 SC and Dursban 48 EC. Chlorothalonil is a nitrile compound used as a preventative foliar fungicide [11]. The fungicide is widely used in plant protection under the tradenames Bravo 5 SC and Gwarant 5 SC. The compound can be found in formulations with many other pesticides. Chlorpyrifos and chlorothalonil residues detected at different sampling times are shown in Tables 1-3. Leaves. As expected, chlorpyrifos and chlorothalonil residues on carrot leaves
Toxicological and environmental aspects of carrot fly (Psila rosae Fabr.) control 121 (5 and 3 days after last application) were in proportion to their application rates. Thus, a higher average initial deposit was recorded for chlorothalonil (48.2 mg/kg) (Tables 2A and 2B). Table 1. Chlorpyrifos residues (mean values ± RSD, mg/kg) in soil and in carrot roots, test 1 Sampling date Weight of carrot Soil Roots 25 July 54 g ± 7 g.13 ±.5.5 ±.6 16 August not analysed.14 ±.7.32 ±.27 1 September 115 g ± 25 g.22 ±.6.6 ±.27 Last application of Nurelle D 55 EC (a.i.: chlorpyrifos+cypermethrin, application rate-.5 l/ha): 2 July Table 2A. Chlorpyrifos residues (mean values ± RSD, mg/kg) in soil and in carrot, test 2 Sampling date Weight of carrot Soil Roots Leaves 28 July 47 g ± 9 g.6 ±.3.4 ±.3 not analysed 1 August 51 g ± 11 g.9 ±.1.8 ±.4 2.93 ± 1.2 16 August 89 g ± 22 g.17 ±.1.8 ±.6 1.92 ±.31 25 August 113 g ± 22 g.11 ±.4.4 ±.2 1.46 ±.54 Last applications of Nurelle D 55 EC (a.i.: chlorpyrifos+cypermethrin, application rate-.5 l/ha): 2 and 27 July Table 2B. Chlorothalonil residues (mean values ± RSD, mg/kg) in soil and in carrot, test 2 Sampling date Weight of carrot Soil Roots Leaves 28 July 47 g ± 9 g not analysed not analysed not analysed 1 August 51 g ± 11 g.16 ±.36. ±. 48.2 ± 25.5 16 August 89 g ± 22 g 3.629 ± 4.754.15 ±.23 4.1 ± 1.6 25 August 113 g ± 22 g.7 ±.56. ±..4 ±.6 Last applications of Bravo 5 SC (a.i.: chlorothalonil, application rate 2.5 l/ha): 29 July and 9 August
122 S. Sadło, M. Filar, E. Szpyrka Table 3. Chlorpyrifos residues (mean values ± RSD, mg/kg) in soil and parsley, test 3 Sampling date Weight of carrot Soil Roots Leaves 1 August not analysed.3 ±.1 not analysed not analysed 16 August not analysed.16 ±.8 not analysed not analysed 1 September 29 g ± 5 g.7 ±.2.48 ±.2.638 ±.172 12 September 49 g ± 12 g.7 ±.3.5 ±.4 1.981 ±.713 Last application of Nurelle D 55 EC (a.i.: chlorpyrifos+cypermethrin, application rate-.5 l/ha): 2 July First order kinetics were found for chlorpyrifos and chlorothalonil when residual concentrations were plotted against time for each data set obtained for carrot leaves (Table 4). The decay rate of chlorothalonil was significantly faster than for chlorpyrifos and its half-life time was about 7 times shorter. Disappearance trends of the two compounds are presented in Figures 1 and 2. Table 4. Kinetic parameters for chlorpyrifos and chlorothalonil decline, carrot leaves Active ingredient Equation R 2 K dec (days -1 ) t 1/2 t 1/1 Chlorpyrifos y = 3.5 e -.29x.999.29 1.4 34.5 Chlorothalonil y = 68.38 e -.28x.981.26 1.5 5. rainfall [mm] 14 12 1 8 6 4 2 4 3.5 3 2.5 2 1.5 1.5 2 4 6 8 1 12 14 16 18 2 22 24 26 28 3 32 34 rainfall residue Figure 1. Disappearance trend of chlorpyrifos residues on carrot leaves.
Toxicological and environmental aspects of carrot fly (Psila rosae Fabr.) control 123 rainfall [mm] 14 12 1 8 6 4 2 5 45 4 35 3 25 2 15 1 5 2 4 6 8 1 12 14 16 18 2 22 24 26 28 3 32 rainfall residue Figure 2. Disappearance trend of chlorothalonil residues on carrot leaves..18.16.14.12.1.8.6.4.2 2 4 6 8 1 12 14 16 18 2 22 24 26 28 3 32 34 36 38 4 root Figure 3. Disappearance trends of chlorpyrifos residues in soil and carrot roots. soil
124 S. Sadło, M. Filar, E. Szpyrka 4.5 4. 3.5 3. 2.5 2. 1.5 1..5. 2 4 6 8 1 12 14 16 18 2 22 24 26 28 3 32 34 36 root Figure 4. Disappearance trends of chlorothalonil residues in soil and carrot roots. soil.7.6.5.4.3.2.1 5 1 15 2 25 3 35 4 45 5 root Figure 5. Disappearance trends of chlorpyrifos residues in soil and parsley roots (likely). soil
Toxicological and environmental aspects of carrot fly (Psila rosae Fabr.) control 125 Roots. About two months after sowing time (and after first treatment), Nurelle D 55 EC was applied against second generation of carrot fly (P. rosae Fabr.). Chlorpyrifos residues in roots were found to be at trace levels.5 and.4 mg/kg (carrot) and.48 mg/kg (parsley). Final levels of chlorpyrifos residues resulted from complex process consisting of washing leaves, absorption by roots, dilution by root growth and successive degradation (Tables 1-3). Due to weather conditions in the 26, average residues in rape carrot (.6 and.4 mg/kg) and parsley roots (.5 mg/kg) were reduced to levels lower than MRL (carrot -.1 mg/kg, parsley -.5 mg/kg) and even the rigorous value of.1 mg/kg. Soil. Chlorpyrifos residues in soil samples taken from under carrot roots were similar to those found in carrot and parsley roots. The highest value detected was.17 mg/kg. Chlorothalonil being a contact fungicide moved from the leaves to the soil and then degraded rapidly (initial concentration of 3.629 mg/kg almost completely disappeared within nine days) and hence could not be detected in the roots at any stage of periodic sampling. The disappearance trends of chlorpyrifos and chlorothalonil in soil (Test 2) were presented in Figures 3 and 4. CONCLUSIONS The decay rate of chlorothalonil was significantly faster than decay rate of chlorpyrifos and its half-life time was about 7 times shorter, Chlorpyrifos in rape carrot and parsley roots was reduced to levels lower than MRL (carrot -.1 mg/kg, parsley -.5 mg/kg) and even the rigorous value of.1 mg/kg, Chlorothalonil disappeared and hence could not be detected in roots at any stage of periodic sampling, If used by baby food producer, fresh parsley leaves should be carefully tested. REFERENCES [1] Commission Recommendation 1999/39/EC of 6 May 1999 amending Directive 96/5/EC on processed cereal-based foods and baby foods for infants and young children. [2] Ambrus A., Lantos J., Visi E., Csatlos I., Sarvari L., J. Assoc. Off. Anal. Chem., 1981, 733-741.
126 S. Sadło, M. Filar, E. Szpyrka [3] Luke M.A., Froberg J.E., Masumoto H.T., ibid., 1975, 12-125. [4] Luke M.A., Froberg J.E., Dosse G.M., Masumoto H.T., ibid., 1981, 1187-1192. [5] Sadło S., J. Plant Protect. Res., 1998, 38(2), 179-184. [6] Dz. U. z 24 r. Nr 85 poz. 81. [7] Dz. U. z 25 r. Nr 48 poz. 46. [8] Dz. U. z 25 r. Nr 18 poz. 97. [9] Dz. U. z 25 r. Nr 242 poz. 247. [1] Dz. U. z 26 r. Nr 192 poz. 1422. [11] Tomlin C.D.S., British Crop Protection Council, 2.